This invention relates to medical therapeutic apparatus. More particularly, this invention relates to electronic circuitry for use in an external defibrillator apparatus. The apparatus of this invention provides an improved, safer defibrillator.
The external defibrillator is a well recognized and important tool for resuscitating cardiac arrest patients. Defibrillation of the human heart is accomplished by applying an electrical waveform t o the cardiac muscle with appropriate electrodes, causing the cessation of rapid uncoordinated contractions of the heart (fibrillation) and restoration of normal beating of the heart.
In the past, defibrillators have utilized various circuitry in an attempt to minimize leakage of current to the patient during charge up. Current leakage is of particular interest in defibrillator circuitry which utilizes semiconductor components for use in switching. However, prior art circuitry has significant limitations and shortcomings. Despite the need in the art for an external defibrillator apparatus and circuitry therefor which overcomes the limitations and problems of the prior art, none insofar as is known has been proposed or developed. Accordingly, it is an object of the present invention to provide a defibrillator apparatus and circuit therefor which overcomes the limitations and shortcomings of the prior art. Particularly, it is an object of this invention to provide an improved defibrillator apparatus which is reliable, durable, and effective at delivering defibrillating charges to the body of a patient. Another object of this invention is to provide defibrillation circuitry which minimizes current leakage to a patient during charge-up. A specific object of this invention is to provide a current leakage attenuation system for circuitry which charges a plurality of capacitors in parallel and discharges them in series utilizing a plurality of semiconductor switches.